1. Technical Field
This invention relates to lawn mowers, and more particularly to a lawn mower having a height adjustment mechanism for enabling an operator to adjust the height of a deck of a lawn mower relative to a ground surface at all the wheels of the lawn mower simultaneously by temporarily, manually engaging a single actuating member.
2. Discussion
Some form of deck height adjustment is common with virtually all lawn mowers. Typically, such deck height adjustment mechanisms incorporate an independent adjusting plate at each one of the four wheels of the mower. Some manually engageable release member is typically associated independently with each one of the adjusting plates and releasably engageable with its associated adjusting plate. Each adjustment plate, in turn, is usually fixedly secured to a portion of an offset axle supporting the wheel associated with the particular adjusting plate. When the release member is engaged, the offset portion of the axle is allowed to rotate which allows the vertical height of the wheel to be adjusted relative to the deck. Releasing the release member causes it to engage the adjusting plate, thus maintaining the adjusting plate stationary, and thereby maintaining the wheel at the desired position relative to the deck. By thus controlling the relative position of the wheel of the deck, the cutting height of the lawn mower blade can be adjusted relative to the ground.
While the above arrangement has proved to be satisfactory for allowing the deck height of the mower to be adjusted relative to the ground surface at all four corners (i.e., wheels) of the lawn mower deck, this arrangement does provide for some inconvenience to the operator. To adjust the deck height, the operator must manually adjust the position of each adjustment plate, and thus each wheel, relative to the deck. Since four wheels are typically employed with most lawn mowers, the operator must typically make four independent deck height adjustments, one at each wheel of the mower, when the deck height is to be raised or lowered.
More recently, improvements have been made to simplify the matter in which the deck of a lawn mower is adjusted to provide a greater degree of convenience to the operator. The assignee of the present application has utilized a form of deck height adjustment mechanism in which the operator is able to adjust the deck height of a mower relative to a ground surface by engaging a single deck height adjustment control. This system is embodied in a lawn mower manufactured by the assignee of the present application, and is disclosed in U.S. Pat. No. 5,230,208. The disclosure of this patent is hereby incorporated by reference into the present application. While the deck height adjustment mechanism disclosed in this patent has proved effective for increasing the ease with which the operator may adjust the deck height, it would be desirable to provide a mechanism which is even simpler and even less costly to manufacture, and which requires a fewer number of independent component parts to accomplish simultaneous adjustment of the deck height at all four wheels of the mower.
Accordingly, it is an object of the present invention to provide a deck height adjustment mechanism for a lawn mower which allows an operator of the lawn mower to easily and conveniently adjust the height of the deck at all four wheels of the lawn mower simultaneously. More specifically, it is an object of the present invention to provide a deck height adjustment mechanism by which all four wheels of a lawn mower may be simultaneously adjusted for height relative to the deck of the mower by simply, temporarily engaging a single actuating member and subsequentially using the actuating member to lift or lower the deck to a desired position before releasing the actuating member, whereafter the height of the deck is maintained at the desired position relative to the ground. Such an arrangement would obviate the need to independently adjust the deck height at each one of the four wheels of the mower one at a time.
It is yet another object of the present invention to provide a deck height adjustment mechanism for a lawn mower which allows the deck height to be adjusted at all four wheels of the lawn mower simultaneously with a single hand, and which is even simpler in construction and lower in cost to manufacture than previously existing deck height adjustment mechanisms.
It is yet another object of the present invention to provide a deck height adjustment mechanism for a lawn mower having a manually, grippable actuating member which allows the height of the deck to be adjusted simultaneously at all four wheels of the lawn mower when the operator grippingly engages the actuating member while simultaneously lifting up on or lowering the deck to the desired height with the same hand. When the deck is positioned at the desired height, releasing the actuating member locks the position of the deck, and thus the height of the cutting blade, at the desired position simultaneously at all four wheels of the mower.